1. Field of the Invention
This invention relates to a resorcinol resin adhesive composition and a method of adhering, more specifically, to a resorcinol resin adhesive composition and the method of adhering using the same, which are excellent in curing rate, and particularly excellent in curability under a low temperature to exhibit excellent adhesion power. Thus, even when it is used in a winter season with a low temperature, it can be cured within a short time to exhibit excellent adhesive properties, whereby a pressing time can be shortened and releasing the pressure can be effected within a short time. Further, productivities using a resorcinol resin adhesive can be improved. Therefore, it is particularly available for the uses of panel bonding such as a plywood and a lumber, or a squarebar, etc. which is required to improve productivity, rub-out of LVLs (Laminated Veneer Lumber) for structure, and wood bonding such as longitudinal seam of woods for structure.
2. Related Art Statement
A resorcinol resin adhesive has been used for bonding of wood materials, and has been used, for example, in a laminated lumber in which a lumber or a squarebar, etc. are located substantially parallel to its fiber direction with each other and bound to the thickness, width and length directions. It has an excellent adhesion strength, water resistance, durability, fire resistance, etc. so that it is available for bonding of laminated lumbers for structure, laminated lumbers for structure with a large section, laminated lumbers for exterior, etc. and for bonding of a tire cord and a rubber, etc.
As a resorcinol resin adhesive for wood bonding, there has heretofore been provided, in general, a mixed material (a paste solution) comprising a resorcinol resin, a curing agent such as paraformaldehyde and a filler such as a coconut shell flour.
However, in the said resorcinol resin adhesive, curing of the paste solution becomes slow when an atmospheric temperature and a temperature of a material to be adhered are low during a winter season, and at a temperature lower than a normal temperature, sufficient adhesive property cannot be obtained. Also, at the normal temperature of 20.degree. to 25.degree. C., it is necessary to cure the paste solution for a long time of 8 to 24 hours.
Since the resorcinol resin adhesive has such a drawback, it is required to install a temperature maintaining device as a preparation equipment or to effect long time pressing of 8 to 48 hours as adhesion conditions.
From such a drawback of the resorcinol resin adhesive, an adhesion process of a laminated lumber for structure generally employed is a process in which lumbers are laminated after coating an adhesive to the lumbers, pressed by a turnbuckle, etc., placed in a thermostat chamber at 30.degree. to 50.degree. C. for 8 to 48 hours to cure the adhesive, and then subjected to releasing pressure and curing. Since such procedures are required, productivity using the resorcinol resin adhesive is extremely bad.
Moreover, in Japanese Patent Publications No. HEI-5-2715/1993 and No. HEI-4-17139/1992, there is disclosed a method for adhering wood materials by coating a resin component comprising a resorcinol resin or a resorcinol.phenol resin and a curing agent separately on the respective surfaces of the materials to be bonded and then laminating these materials.